Some Results on Exponential Synchronization of Nonlinear Systems

Based on recent works on transverse exponential stability, we establish some necessary and sufficient conditions for the existence of a (locally) exponential synchronizing control law. We show that the existence of a structured synchronizer is equivalent to the existence of a stabilizer for the individual linearized systems (on the synchronization manifold) by a linear state feedback. This, in turn, is also equivalent to the existence of a symmetric covariant tensor field, which satisfies a control matrix function inequality. Based on this result, we provide the construction of such a synchronizer via backstepping approach. In some particular cases, we show how global exponential synchronization may be obtained